Bosch HBN756 A US/01 Oven

I'm having a hard time diagnosing poor preheat times. Also,the oven is exiting preheat before the target temperature is reached. Lots of clicking going on. I'd like to get the service manual that will allow me to go through each element and fan one at a time till I can find the culprit.

"Suds are not good"
"They write directions for a reason"
"Make sure you're using it right before you say it's not working correctly"
"If if has a Diagnostic Test Cycle, Run it before and after you fix it!"
"Doing the same thing over and over again and expecting different results is insane""For every complex problem there is an answer that is clear, simple, and wrong."